Apparatus for photographic image production



y 9,1940- P. 5. SMITH 2207,419

APPARATUS FOR PHUTOGRAPHIC IMAGE PRODUCTION Filed Sept. 6, 1939 6 Sheets-Sheet 1 ATTORNEY July 9, 1940. P, SMITH 2,207,419

APPARATUS FOR PHOTOGRAPHIG IMAGE PRODUCTION Filed Sept. 6, 19:59 6 Sheets-Sheet 2 INVENTOR 8:04 /P Jzwvzfy 5/717 NEY July 9, 1940. P. s. SMITH 2,207,419

APPARATUS FOR PHOTOGRAPHIC IMAGE PRODUCTION Filed Sept. 6, 19:59 6 Sheets-Sheet 5 ATTORNEY July 9, 1940. P. 5. SMITH APPARATUS FOR PHOTOGRAPHId' IMAGE PRODUCTION Filed Sept. 6, 19259 6 Sheets-Sheet 4 July 9, 1940. P. s. SMITH APPARATUS FOR PHOTOGRAPHIC IMAGE PRODUCTION Filed Sept. 6, 1939 6 Sheets-Sheet 5 rill ATTOR EY July 9, 1940. P. 5. SMITH 2,207,419.

APPARATUS FOR PHOTOGRAPHIC IMAGE PRODUCTION Filed Sept. 6, 1939 e Sheets-Sheet e PE i an Q A A ii Q &% 4 g m 3 7 n? iwi INVENTOR fiI/LI'P STANLEY SMITH BYW U O NEY ATT Patented July 9, 1940 I more STATES PATENT oFFlcs APPARATUS FOR. PHo'roGaAPnIo IMAGE PRODUCTION Philip Stanley Smith, Camden, N, J.

Application September 6, 1939, Serial No. 293,537

20 Claims. (Cl. 8816.6)

This invention relates to photographic pro- Figure 4 is a perspective view on a still smaller ductlon and apparatus for photographic" image scale of such a motion picture camera illustratproduction. ing also the manner in which certain of the This application is a continuation in part of control apparatus may be associated therewith;

5 my application Serial No. 90,118, filed July 11, Figure 5 is a central vertical sectional view, 5

1936 now Patent 2,176,108. with certain parts broken away or omitted, and In United States Letters Patent Nos. 1,927,925 on an enlarged scale, substanti l y as ee l n and 2,025,731 of Ludwig M. Dieterich, are dethe lin 5-5 of Fi u 1 r the line 5-5 of scribed methods and apparatus for producing ure 3, showing an illustrative form of lens mountphotographic pictures having the effect of relief ing, diaphr and iris diaphragm, d acllll- 10 or depth; one of the objects of this invention is Ming mechanism t e to provide a method and apparatus of the just Figures 6 and are ws e that Of F gure 5 mentioned character that will have a su erior u y fra nta y, showi rtain alternarange of change or variation in effect, that will live forms of lens actuating Control means;

be widely flexible. of control to facilitate meeting Figure 8 s a end l vat n as s from t 15 widel ,varying conditions met with in practice, l t i F u 5, ta n parts e n v and that may be controlled and operated in 9, shown in Section, and simple and dependable manner. Another object Figures 9, 1 d 11 are electrical a s is to provide for greater as a d speed of of circuit arrangements and electrical systems trol, particularly where, when image-recording for achieving Certain controlling and testing ac- 20 or reproduction is being made of a changing t O s and operations. scene, as in motion ictur h t h and t Similar reference characters refer to similar make possible successive predeterminations. of Part5 llhmllghollt the Several ew of the drawthe factors affecting the operation of the appa- 1 8 ratus in advance respectively of successive Certain features of y invehtion are est ilchanges in conditions of the sa scene or lustrated when embodied for motion picture changes in the scene. 1 photography and in the following description the Another object is to improve upon th m t d reference to the latter is to be interpreted as iland apparatus of the aforesaid Dieterich patents lllSliraliil/e f0!v my lnVentiOIl contemplates and in a. manner to make the same more readily and. includes Still Photography as Well e y. more widely adaptable to the widely varying rethe prod on o images of y Scene, j c r quirements of motion picture photography and the like- In Figures is S own a ot D also in a manner to achieve a greater variety of lure camera having a Casing 30 transversely effects. Another object i i n r t improve slidable on the base 3| in suitable ways 32, 33, and to extend the methods and apparatus of tlie base 3| having any u t pp Caslng 35 aforesaid Dieterich patents. Other objects will has suitable film reels or holders 36 o be in part obvious or in part pointed o th r the film 31, the latter being in the usual strip lnafter. v form and being fed through any suitable film- The invention accordingly consists in the feadriving mechanisms (not how including the 40 tures of construction; combinations of elements usual Shuttle mechanism, Shutter, the like,

arrangements of parts, and in the several steps 9 of y Suitable form. x p in etand relation and order of each of the same to e c Patent 2,025,731. Casin 30 has a y tone or more of the others, all as will be illusb e Source of driving power for these fi htratlvely described herein, and the scope of the flnlsms, such as an electllc motor 33 connected application of which will be indicated in the foli a y su l way to dr ve the main shaft.

lowing claims, l 3ase 3| (see Figures land 2) has an upright In the accompanying drawings in which are hollow standard 39 with respect to which casing shown by way of illustration sev ral of th a i- 30 is likewise slidable, and upon the front of the on possible b i t of t mechanical standard 39 is rotatably mounted, by stud shaft electrical features of my inventi n, 40, a disk or plate 4| which carries a number of Figure 1 is a plan view on a small scale of a lenses or lens systems, illustratively four, as at camera, illustratively a motion picture camera; 3. y One Of which y thus be D Flgure 2 is a side elevation thereof; sitioned relative to the aperture, shutter and Figure 3 is an end elevation as seen from the film of the camerafThese lens systems may be of ht in Figure 1; i any desirable or suitable construction and at u least one of them, illustratively lens system 42,

embodies certain features of my invention, and hence, in Figure 5, it is the lens system 42 that shown, positioned by rotary plate 4! for having the film 31 exposed therethrough, camera casing 50 being for that purpose shifted into the position of Figure 1. In Figure 5 there is indicated diagrammatically the shutter 46 coacting with an aperture plate i! to control the exposure of the film 3?.

The lens system it, according to certain teatures of my invention, preferably comprises any lens system constructed according to the abovementioned Dieterich patents; thus, it may comprise a lens system of the type shown in Figures 2, 3 and 4 of Patent 1,927,925 in which relative movement between three lenses takes place or, as illustrated in the drawings, it maycomprise the form described in that patent with respect to Figures 9, 10, 11 and 12 or the form described in Patent 2,025,731 where relative lens movement is achieved by moving one lens relative to the rest, all for the purpose, as described in the Dieterich patents, to achieve upon the receptive element or film an infinite number of images of the scene or object, each, however, corresponding to a different focus or plane of sharpness and all of the recorded images being or the same size and registering throughout, thereby giving the recorded effect of relief or depth in the scene or object. 1

Thus, in Figure 5, lenses 618, 59, 5D and 5t may correspond "respectively, in construction and action, to lenses 26, 27, 28 and 29 of Figures 2 and 5 of Patent 2,025,731, or to lenses 226, 227, 228 and 229 of Figure 9 thereof, or to lenses 4, 3, 2 and 1 of Figures 9-12 of Patent 1,927,925.

Lenses 50, 5| are mounted in an aperture in a disk-like plate 52 which rests against and is secured to the rotatable mounting plate 4! of the camera. 1

Movable lens 49 is carried in a sleeve 53 secured in the aperture of a sheet-like flexible or resilient preferably metallic disk-like support 54 which has a ring-shaped armature 55 secured thereto through anon-magnetic spacer 56, armature 55 having a winding 51 thereon, being spaced in theannular air gap between the two-part annular field core structure 58-59, shaped, as shown, to receive the annular winding 60. The core structure 58-55 is carried in a ring member 6| preferably non-magnetic and se'cured to lens plate 52 and having an annular recess 62 in which is seated the peripheral portion of the spring support 54 which is clamped therein by a clamping ring 63 secured to ring 6| in any suitable way.

Ring 6| is out out as at .64 to form a seat for a ring armature 65 secured thereto andcarrying a winding 66 and to provide a space to accommodate a companion ring armature 61 having thereon a winding 58, core, 61 being secured to the spring diaphragm-like lens support 54.

Lens 48 is suitably secured in a"sleeve-like mounting carried by or suitably secured to a disk supporting member 69 that overlies the ring members 6| and 63 and is suitably clamped thereagainst. All of these lens supports and mountings are so shaped and assembled and secured togethenas by'clamping screws, that the optical axes of the individual lenses are coincident and hence coincide with the optical axis of the lens system. The flexible disk support it of the movable lens 48 yields for efiecting movement of the lens but without tilting of the latter so that theoptical axis of the movable lens is always in coincidence with the optical axis of the lens system, throughout its range of movement.

Fitted and secured against part 69 is 'a-ring member 10 and in its aperture is mounted a variable iris diaphragm H of any suitable construction to permit adjustment of the aperture and adjustable in any suitable manner as, for example, by a ring gear 12, the rotary position of which, and hence the size of the aperture formed by the iris diaphragm, may be set as by a bevel gear it on the end of a shaft it rotatably mounted in the ring til.

Also alined along the optical axis and positlonal'ole either in front or in rear of the iris diaphragm ll, lllustratively in front thereof, is amechanism for varying the amount of light with change in focus where that action as tainght in the said Dieterich patent is desired, and preferably this variable. diaphragm comprises four plate members 775, ldfill, it (see also Figure 8) preferably arranged in opposed pairs and presenting suitably shaped aperture-outlining edges, illustratively square. These plate members and their actuating means are carried in a frame ring l9 and they are identical in construction, the four units being spaced 90 apart in the frame ring it.

Thus, each plate is carried at one end of an L-shaped link 86 that extends through the cylindrical core part til which with its companion annular core part 82 encases a winding 83, core parts 8t and 82 providing an annular air gap into which extends a ring armature 84 having therei on a winding 85, armature 84 being secured to a flexible resilient sheet metal disk 86 at whose center the link 60 is secured while its peripheral portions are clamped between the annular frame parts 81 and 88. Frame part 88 has the core structure 8l-62-secured thereto (see Figure 8). while frame part 87 has secured thereto a rigid yoke at whose center is rotatably secured the inner end'of an adjusting screw 90 that is threaded into a segment 9| thatcloses the recess or cut away parts of the frame ring 19 in which the unit 808|,-8382888 1--89 is slidably mounted for movement along a radius and hence-toward or away from the optical axis, springs 92 being interposed between the yoke 89 and the closure part ill to take up lost-motion or back lash. As shown in Figure 6 the frame ring I0 that carries the iris diaphragm Il may be constructed to take part in the mounting of the four units of the just described character; frame rings 19 and 10 may be secured together as by Preferably the shaft 14 (Figure 5) for adjust ing the iris diaphragm H is adjustable both manually and by suitable electromagnetic means.

j Thus, it may have a knurled adjusting knob 93 throughout a possible 360 rotary movement, or

fraction thereof, according to the degree of energization of the motor, the shaft 96 of the motor being connected to drive the shaft 14 through a gear box 91 and the-bevel gears 98 and 59; the

gear ratios are preferably so selected that the range of rotary movement of the servo-motor is suflicient to change theopening made by the leaves of the iris diaphragm H from zero to a maximum. If desired, the servo-motor drive may be disconnectable, as, for example, by splin- 7gcult arrangement and control, and of the electri ing the gevel gear to the shaft I4 to permit shifting it manually out of engagement-with the driving gear 98, thu'sto leave the iris diaphragm only manually controlled.

The various annular or ring-like frame members (Figure 5) may be suitably, in whole or in part, encased in a suitable casing. I00 which may take part in mounting the assemblage on the rotatable front plate ll, as by the flange I0! of the casing and screws I02. The right-hand end of the assemblage may be closed on or finished off as by a disk-like plate I03 (Figure 5) which may be secured in any desired way to the frame ring I9 and which has a central aperture I00 preferably circular and with its axis coincident .with the axis of the lens system, the aperture being of appropriate size or diameter to pass therethrough sufiicient light from the scene or object for appropriate action or control by the various abovedescribed movable parts. I

In Figure 9 is shown diagrammatically a cir cal parts above described, the coils affecting the relative lens movement are indicated at 51, 60,

56 and 68, the servo-motor at 95, the camera motor at 38, and the four pairs of diaphragm plate moving coils are shown at 83-45; these parts, and a photoelectric cell I05 related to the camera as later hereinafter described, are all associated as above described, with the camera mechanism shown in Figures 1, 2 and 3, and suit-- able conductors, which may be formed into several cables, as shown at I05 and I01, in Figure 4, extend their circuits to a portable cabinet I00 having an instrument or control panel I00; in the cabinet are housed the various electrical apparatuses about to be described while the various indicating instruments and manual controls about to be described are conveniently grouped for easy visibility and easy manual control in the face of thepanel I 09, as is diagrammatically indicated in Figure 4. A cable IIII leads from the cabinet I08 and has a connecting plug III which may be plugged into" any plug receptacle associated with a suitable power circuit, such as a commercially available 60-cycle 1l0-volt alternating current circuit, the latter being for convenience diagrammatically indicated .in Figure 9 at 2.

From Figure 9 will be seen a circuit leading from the driving motor 30 to the power circuit, through a suitable control, such as a switch III.

Winding 60 I preferably energize by unidirectional or direct current to set up a magnetic field or flux in the airgap (Figure 6) in which is contained the winding 51 and armature 55, and winding 51 I energize with periodically varying current,'such as alternating current, to produce a magnetic field or flux which, like the current produclng it,; is also periodically variable and in the illustration is alternating; The resultant reaction between these magnetic fields is to cause an oscillation of the armature 55 and winding II at the frequency of the variation in the current energizing winding 51; such oscillation is permitted by the flexibility or yieldability of the diarectifier Ill interposed between the winding 5 0 and the alternating current source 2, and in the direct current circuit of the winding I interpose a rheostat I l 5 and an indicating instrument, such as an ammeter II5 to indicate the degree of energization of winding 50 as determined by the rheostat I I5.

Since, as will later appear, the frequency of the current energizing the winding 51 is preferably variable, I provide, as diagrammatically indicated at II! a suitable means, energized from the source II2, for providing a frequency which may be varied or changed at will; this means may comprise any suitable arrangement such as,

' able electronic conduction tube or tubes with appropriate circuits, preferably variable and preferably including an amplifier, in any suitable or well-known form, to produce alternating potential or current of selectable frequency. Whatever the form of the device II'I, suitable means for changing its frequency are provided, illustratively in the form of a variable resistance or rheostat of which, in Figure 9, two are shown at Ill" and I I 8 either of which may be put into effective circuit control by a selector switch S for a preferred purpose later described.

From the frequency changer II], a circuit extends through a suitable voltage regulator H9 to a transformer I20, preferably to reduce the voltage, and the output of transformer I20 is passed through a filter I2I to the winding 51 by way of either of two rheostats I22 and I22 selectably putting in controlling circuit relation by a selector switch S. An indicating instrument preferably in the form of a voltmeter I23 indicates the energization of winding 51 as determined by the rheostat.

Lens 40 may thus be vibrated or oscillated at the frequency of the alternating current energizing the armature winding 51; its movement is, of course, relative to the stationary lenses 40, 50 and 5| and if its oscillation is within the limits of a certain range 'of possible movement relative to the remaining lenses, all as. described in the aforesaid Dieterich patents, the plane of sharpness or focus is shifted back and forth from the above-mentioned photoelectric cell I05 which is suitably mounted '(see Figures 1 and 3) ,at the side of the movable casing 30 so that the axis of the aperture I 24 of the cell casing I25 is in line with the optical axis of the lens system and the light sensitive element of the cell I05 is at the image plane,- after appropriately shifting casing 30;

The cell I05 hasits electrodes included in a circuit in which is included a suitable source of potential I26 (Figure 9) which is preferably derived, under the control of a switch I21 from the principal or primary source I I 2 the source I26 may comprise any suitable device, well known in the art, for providing a suitable potential in the circuit of the photoelectric tube I05. In the output circuit of the photo-cell 905 is included a suitable measuringor indicating device I20 that'" is preferably of a sensitive and precision type,

such as a vacuum tube type of A. C. voltmeter,

photo-cell and also variations in such flow; this for indicating current flow in the circuit of the indicating means I28 may, if desired, include an lib may be set for any desired frequency while the setting of rheostats i22 and M achieve energization of windings h'land Gil, setting-movable lens 3% (Figure 6) into oscillation; the iris diaphragm ll may be manually set by control Q3 and the diaphragm plates 115, it, W and T18 manually set by the unit-adjusting screws lli (Figure 8) to determine the desired mean or average value of light to pass through the now active lens system to the image plane at which, however, is now the light-sensitive element of photocell ace.

Rheostat H5 is now set to a'value as indicated by the ammeter lit either in current.intensity or other indication for which the instrument may be calibrated, to cause the winding til (Figure 5) to set up the desired value of unidirectional fiuz': in its annular air gap in which is winding 51 whose alternating current energization may now be set or controlled by rheostat 522 the voltage being indicated by the voltmeter I23 which may also be otherwise calibrated. Initial closure of rheostat I22 starts the lens '49 vibrating to each side of its normal neutral or mid position and as the energization of winding 51 is increased the amplitude of oscillation increases, and with these effects indicator I28 in the photo-cell circuit gives an increasing indication, the setting for rheostat I22 corresponding to the proper and complete range of relative lens movement being that at which the indicator I28 gives a maximum indication. Thereby, I make certain thatzthe movable lens in the lens system does not over-step its limited range of movement within which in-focus and out-of-focus images are equal in size and also register at the image plane. i

If the amplitude or distance of travel of the movable lensis outside the above-mentioned critical range relative to the remaining lenses,.

the images produced upon the photo-cell element will in effect be blurred in that out-offocus images do not register concentrically with in-focus images and thus 'theeffective light transmitted to the photo-cell is in quality or quantity different from the light which would reach it if the in-focus and out-offocus images were of the same sizeand in registry. Accordingly, improper relative movement between the lenses causes the indicator I28 to give an indication, registering a fluctuating light density,

in terms of alternating current, due to. the periodic movement or oscillation of the movable lens at the frequency of the alternating current 39- lected by control II8 During these testing operations filter I30 is switched into its circuit by its switch I3I. Interference with the testing system by foreign 'or outside fluctuations is negatlved by the action of regulator I I9, preferably of the core-saturation type, which negatives possible fluctuations in the source II 2, and by filter I2I which is adjusted to suppress all frequencies other than that selected by the control H8 that being. the frequency of lens oscillation. Filter I30, connected in parallel by its switch I3I in the amplifier output circuit,-

is proportioned or adjusted to suppress all frequencies other than the frequency selectedby control lid and hence the frequency of lens relative movement, thus suppressing variations in normal light reaching the image plane and Next, the light controlling diaphragm plates l5, 76, Ill, Hill, having already been. approximately set by the adjusting screws 9d, may now be preciselyset by the screws in relation to a more precise setting, if necessary, by control Q3 of the iris diaphragm. 'I'he oscillation of the'movable lens :39 is now halted, as by setting rheostat I22 or rheostat M5 to its off position, and the effects of these settings of the plates andiris diaphragm gaged with reference to their respective effects upon the photo-cell and its circuit; firstly, the iris diaphragm is set to make sure that sufficient light falls uponthe image plane, as'i's necessary to photograph the most distant objects in the scene, and here again the indicator I28 may be appropriately calibrated in terms of suitable factors, such as distance ironr the camera.

Preferably, the just described settings of the iris diaphragm are achieved by control of the servo-motor 95 whose circuit,'as shown in Figure 9, extends to the source of alternating current II 2 through a selector switch S by which either of two rheostats I32 and I32 maybe included selectively in the motor circuit. The settings of'the iris diaphragm may thus be varied by either of these rheostats which may be like- I 83, by 'altemating current energy of the desired frequency, derived from the frequency changer III through a regulator I34 and a suitable stepdown transformer I35. The diaphragm plates are thus set into oscillation at the frequency selected by the control H8 The circuit of windings 83, preferably arranged serially, includes a selector switch S by which either of two rheostats I38, I36 may be injected into the circuit, and also an indicating instrument, such as an ammeter I 31 which may be calibrated in other factors than current values; by whichever rheostat is put in circuit by the selector switch S, the energlzation of windings 83 is brought to a suitable value-to cause each to produce the desired unidirectional magneticfield (Figures 6 and 8) while the amplitude of vibration or oscillation of the plates may be determined by either of two rhecstats 938 or I38 selectively brought in circuit by a selector switch an instrument 139 in the form of a voltmeter but calibrated also in other factors indicating the energization of armature windings 85, the latter being connected in parallel.

For the given set of conditions theretotore established, the rheostats, such as I36 and I38" (with selector Switches 8 and S in position 1)- are now manipulated one'witli respect to the otheruntil the indicator I28 in the photo-cell circuit reaches a maximum indication, the lat-- ter corresponding to proper or optimum oscillation of the diaphragm plates at the selected frequency.

The movable lens may now be set into oscillation again by setting rheostats I I5 and I22 to the values previously determined by the photocell testing circuit, and now switch I3I of the filter I30 closed to-bring the filter into the circuit to check the composite action of relative lens movement and diaphragm plate movement. If

the indicator I28 now indicates a minimum, determined by manipulating either or both of rheostats I36 and I38, the system is in appropriate setting and ready for operation. Photographing of the scene or object may now be proceeded with.

The above procedure is set forth by way of indicating how any set of adjustments may be safely arrived atwith the aid of the photo-cell test according to whatever are the conditions met with in the scene or object whose images are to be recorded. But preferablythe photo-cell cir- 25 cuit is used to calibrate the various controls and I indicating instruments in terms of light values, distances from the camera, frequency values, diaphragm movement, iris diaphragm adjustment, and the like, or, in so far as the'control features of my invention are more broadly concerned, such calibrations may be achieved otherwise, for example, empirically. With all of the controls and indicating instruments thus calibrated, it being noted that selectable controls like pairs of rheostats are duplicates and are similarly calibrated,

and with all of the calibrations and controls ac-' cessible in the panel I09 (Figure 4) of the control cabinet I08, it is now possible to achieve a quick adaptation of the system to any particular scene requirements.

' For example, and noting first that the selector switches are suitably synchronized as by mountdriving motor switch Ill being, of course, then closed, photographingv of a-scene or object may he proceeded with with entire assurance of proper functioning of the lens system and related parts. Should conditions in the scene change, some of these controls may be shifted or adjusted during the photographing while on the other hand should such changes in the scene or sequence being photographed take place as to require a more radical change in setting, controls I22, I92", Ia n-I38 and I I 8", or such of them as may be required, are given such diflerent settings as may be' needed, all while these controls are kept out of circuit due to the selector switches being in position 1. At the moment when the scene or sequence changes, the new settings are brought into eflect by operating the switch-control I to set the selector switches on position 2, thus taking the former'set of controls I22", I92, etc., out of circuit. The latter may now be manipulated as may be necessary to'prepare for a subsequent shift or change in requirements and brought into effect by a subsequent shifting of the selector switches in synchronism to position 1 i Windings 66 and 68 are connected in parallel through a reversing switch I42 and are supplied with direct current energy derived from the source 2 through the rectifier I43, and by way of a circuit which includes another selector switch S by which either oftwo rheostats I44 and I44 may be used to control the energization of these two windings, the extent of change is indicated by an ammeter I45 calibrated in suitable factors as will now be clear.

If windings 68 and 66 are energized, under control of reversing switch I42, which is also in the panel I09 (Figure 4), so as to magnetically oppose each other, the diaphragm spring mounting 54. (Figure 5) of the movable lens 49 is biased toward the right and hence movable lens 49 is made to assume a different normal or neutral position than it did theretofore. If switch I42 is reversed, the magnetic fields of these windings attract each other and the biasing is toward the left. The amount of biasing ineither direction is determined by either of the rheostats I44, I44'.

During oscillation of the movable lens throughout its' normal and maximum range, the focus of the lens system is changed from a point near the camera to a point infinitely remote from the camera, while lessening the energization of winding 51 as by setting rheostat I22 or I22 is effective to shorten the stroke of oscillation while maintaining the same middle or neutral point as above, thus shifting the focus again throughout each stroke but now throughout a shorter range positioned intermediate of the point near the camera and the point infinitely remote from the camera. By causing the electro-magnets 66 and 68 to effect a controllable or variable bias, the neutral point to each side of which the lens oscillates is shifted toward one end or the other of the original or normal or maximum range of movement, according to whether these magnets oppose or attract, and thus any portion of the normal range of relative movementmay be selected. I

For example, scene orportions of scenes of small depth that require equal movements of the movable lens 49 to either side of its normal neutral position may be photographed as above de scribed, leaving rheostats I44 and I44 in open position, thus avoiding the biasing action, and utilizing rheostat I22 or I22? to select the desired amount of these equal movements of the movable lens to either side of its normal neutral position, thus concentrating the action of the lens system in changing focus While maintaining size and registry of in-focus and out-of-iocus images throughout a corresponding depth of scene between a point intermediate of nearness to and the camera, the reversingswitch I 42 is actuated at the appropriate time to reverse the biasing eii'ect and thus to select adifierent portion of the normal range of relative lens movement.

v It will be noted that the various controls, such as the rheostats, are constructed each to have an off position; thus, for example, if it is desired todispense with the diaphragm plate movement, rheostats I38 I38'", I38, I3Ii are simply set to the oif" position.

To obviate the need or desirability of manually operating the reversing switch I42 simultaneously :with the switch-over control I4I I prefer to synchronize' the operation of the two as by an arrangement shown in Figure 10 where the separate windings 66 and 68 aredispensed with and, as is shown in Figure 6, I employ a singlewinding 68 unidirectionally energized but mounted adjacent to the winding 51 and hence magnetically related also to the armature 55, and .utili ze the unidirectional magnetic field produced by winding 88' to coact, according to the direction of current flow through it, with the unidirectional field produced by the winding 60. In Figure 10 winding 68 is again energized from the rectifier I43 but through a circuit that includes two switch arms I42 I42 mounted on the control shaft I40 to be moved thereby and synchronously with the selector switches 8 S", 8 S S", S"; in Figure lo-these switch arms and selector switches have six contact positions, as shown, but as to reversing switches I42, I42 contacts 1" and 2" are electrically tied together as are also contacts ((3!) 44.!

Just as each position 1 and 2 of the selector switches of Figure 9 has in circuit with it a rheostat so also each position "1," 2," "3 and 4 of the corresponding and similarly numbered selector switches of Figure 10 has a rheostat in circuit therewith, resulting in flexibility of control and manipulation, as follows:

First,.it will be noted that with the shift-over control I4I in either position 1 or 2," the circuit arrangement determined by reversing switches I42, I42" is the same so that no change in direction of current flow takes place in shifting from position "1 to position 2;" a similar arrangement, but with the direction of current flow reversed. exists with respect to positions 3" and "4) Accordingly, and assuming all of the selector switches S to 8' to be imposition 23 a given operating condition exists according to the setting of the controls I22 I44 I36 I3I .II8 and I32 reversing switches I42", I42 are also in position "2" so that current flows through the biasing winding 88 in a corresponding direction, thereby selecting a range of relative lens movement that is toward one end of the entire or maximum range, to an extent determined by the adjustment of controls I44 and I22", thus causing the lens systemto bring 'into prominence or sharpness in image registration those parts of the scene corresponding to that selected portion of the available range of movement, illustratively I) near the camera.

with photographing proceeding with such a setting and assuming that the next sequence of the same scene or the next scene requires image registration corresponding to a change in the I. biasing action but without reversal of current ilow, the controls l22, I44", "8, I38, 8 and bringing these new settings into eilect'is reached, I the operator switches the switch-over control I ergy supplied t to position thus making effective the just-set controls.

Should a reversal in biasing action of coil 88 be required, the operator sets controls I22', I 44*,

I36, I38", II8 and I322 or such of them as requirements dictate, thus to set upthe controls for the ensuing requirement.

" the biasing widing 68 but in reversed direction,

causing the movable lens to oscillate through a different portion of its normal range, now toward the other end, causing the lens system to bring into prominence or sharpness in image registration those parts of the scene corresponding to that selected portion of relative lens movement, illustratively remote from the camera.

On the other hand, if a biasing action is not needed, any one of the controls I44, I44, I44", I44, according to which one is to be made efiective upon the subsequent setting of the selector switch S is set to its oil'" or open circuit position, whence the oscillation of the movable lens proceeds throughout the entire range of relative movement or any smaller portion thereof but always with respect to the midpoint of its normal range, according to the setting of the corresponding rheostats in the circuits of windings 51 and 60 In Figure 11 I have shown a further simplification of the windings controlling any movable lens, such as the movable lens 49, in that I may dispense entirely with the biasing windings 66 and 68 and even also with thebiasing winding I58 of Figure and utilize only windings 80 and 51. Thus, in Figure 11, I have arranged winding 51 to be energized not only by altemating current but also by a reversible unidirectional current so that the reversible unidirectional fluxof the latter current maycoact with the unidirectional flux of the winding 80 to achieve the above-described biasing action, preferably by way of a control, as already above described and as shown in Figure 11.

The circuit arrangement of Figure 11 is exactly like that of Figure 10 excepting that winding 68' is dispensed with and winding 51 is connected in its place, but through a suitable choke -coil I41, the latter passing direct current therethrough but pgeventing alternating current enthe winding 51 from passing into the circuit supplying that winding with direct current. Alternating current energy is supplied to winding 51 preferably by a transformer I 48 interposed between the winding and its supply and control circuit, a condenser I49. being interposed at a suitable point to permit alternating current to flow through it to the winding 51 but to block the flow of direct current energy into the transformer circuit. The indicating instrument in the form of a voltmeter I23 to indicate the alter nating current energization of winding 51 is mounted as above noted on the panel I" (Figure 4) and is connected across winding 51 but through a condenser III that blocks the iiow of direct current energy to that instrument.

Thus, when the direct currentis cut off from winding 51, as by setting to the "off" position whichever of the rheostats 144, I4, I44, I44 isto be made effective by the selector switch 8'.

When the lattermatures, switch-over control I is now switched no biasing action takes place. The amount of biasing action, when desired, is controllable, and

also its direction, by the just-mentioned rheostats and the reversing switches I42", 2, according to the position of the selector switch S, in the same general way as was described in' connection with Figure 10.

Thus, I am enabled to achieve wide flexibility of action or control and the many widely varying conditions met with in practice can be quickly, and reliably taken care of. Moreover, it will be seen that I am enabled to make changes in the action of the systemwithout interrupting continuity of camera action or photographing, clue to the switch-over control above described, and thereby also I am enabled to achieve greater speed of motion picture production or photography and also with minimum risk of film spoilage. As noted above, in the preferred form of control, the circuit constants may be set up by way of one set of controls while another set of controls is actually operating in their respective circuits. p i

It will also be understood, however, that where conditions may require it, I am enabled to change the action of the lens system or of the diaphragm plates or both during the exposure of the motion picture film during any single scene or sequence; the various rheostats, when once initially set to suit the beginning of a scene or sequence may be manipulated to change the action of the apparatus according to changing requirements of the scene or sequence.

As earlier above noted, the various controls which are operable to set the constants'of the lens system throughout any selected portion of its normal range of relative movement; throughout the latter constancy of size and registry of images corresponding to different planes of sharpness from a point near the camera to a point vastly remote from the camera are achieved but by selecting any portionof that range of movement, the objects or that portion of the scene within the planes ofsharpness that correspond to the selected portion'are brought into prominence on the ultimate film, as against objects or portions of the scene outside of the thusselected planes of sharpness.

I may, however, cause such a biasing of the movable lens as will cause its stroke of oscillationto overstep the corresponding end of the normal range of relative movement and thus register on the film geometrically similar images of different sizes, thus achieving a so-called softening effect.

Nicety, aswell as wide flexibility of control is achieved. For example, in Figures and 11, if a reversal oi biasing action has to be eifected under circumstances which require moving the selector switches through an intermediate position, as, for example, in shifting from position "1 to position "3" and thereby passing over position 2, any effect upon the operating mechanism of the, camera as might be caused by passing the.

selector switches through an intermediate contact position, like position "2 in the just assumed example, may be avoided by setting to the off position the rheostats that are in the circuits corresponding to the selector switch position passed over; in that way, any chance of the transition even though the latter is accomplished very rapidly, being'accompanied by an undesired effect, may be avoided. Or, for purposes of such a transition, and just prior to effecting the transition, the controls or rheostats in the circuits of the position to be passed over may beset to duplicate the conditions set by the corresponding controls in the circuit position from which the transition is to take place; the circuit and operating conditions thus established, for example, foFposition 2, in Figures 10 and 11, to be passed over and moving from position 1 to position 3 may thus be made to be the same as theretofore existed at position 1.

It might be noted that the'selection of frequency of oscillation is of great advantage. In motion picture photography, for example, the

frequency or rate of exposure of film frames isusually about twenty-four frames per second; I

change the frequency of the system to match, or become a multiple of, the frequency of frame exposure. Preferably, the frequency of oscillation is comparatively high for I have discovered that I ani enabled to materially-if not entirely,

avoid so-calledihalatlon, caused, as is known, byreflection or refraction of light on or within the film itself. In thus making the relative movement take place at a frequency of oscillation greater than the frequency of frame exposure, theeffect is to eclipse at high frequency the images projected upon the exposed camera element or film, bearing in mind that, as the lens system! shifts the focus from one plane of sharpness to another, light from the object or points within that one plane of sharpness is, in effect, cut oil, and light coming from the object or .points in another plane of sharpness is what is directed onto the film. The higher the frequency of this eclipsing action, the less dense will be the light striking the film per cycle of the frequency of eclipsing.

The selectable frequency may be of substantial magnitude, approaching audio frequency, for example, and due to the above-mentioned effects the image recording is sharper than where lower frequencies are employed; accordingly, it is also possible to vary the sharpness of recording by and the operator may, by such acontrol as above described, vary the frequency during operation 'of the camera or speedily and quickly prepare for subsequent changes as might be required to suit the technique, style or artistry desired.

Thus, it will be seen that there has been provided in this invention a photographic method and apparatus in which the various objects hereinbefore noted, together with many thoroughly practical advantages, are successfully achieved. It wfll be noted that precision of control and acvarying the frequency of oscillation of the lens focus images of a scene or object corresponding to a plurality of different planes of, sharpness, means mounting said lenses in axial alinement and including movable means capable upon actuation of effecting relative axial movement between Esaid lenses, actuating means for effecting movement of said movable means in recurring cycles throughout said certain range, a plurality of control means for varying the action thereof, reversible means acting upon said actuating means to restrict movement of said movable means toward one or the other end of said certain range, a plurality of control means for said last-mentioned means for varying its action and including means for reversing its action, and selector means operative upon said controlling and reversing means to make at least two of each of said plurality ofcontrol means selectable for each direction of action as determined by said reversing means.

'7. An apparatus of the character described, in which there is a lens system having a plurality of lenses between which relative axial movement may take place and which are corrected 'to produce, at the image plane of said system and for a certain range of said relative movement, equality of size and registry of infocus and out-of-focus images of a scene or ob- Ject corresponding toa plurality of different planes of sharpness, means mounting said lenses in axial alinement and including movable means capable upon actuation of effecting relative axial movement between said.lenses, means energizable by alternating current energy for actuating said movable means in recurring cycles at the fre-- quency of said energy, a source of alternating current energy having a plurality of control means therefor for changing the frequency of its output, a plurality of control means for varying the energization of said electromagnetic means, and selector switch means for determining which of said first plurality of control means and which of said second plurality of control means is eflective at one time, thereby to permit ineflective control means thereof to be set or adjusted to be' subsequently made effective by said selector means.

' means mounting said lenses in axial alinement and including movable means capable upon actuation of effecting relative axial movement between said lenses, and means for actuating said movable means, said actuating means comprising means producing a unidirectional magnetic field, a winding mechanically connected to said movable means and positioned so that? its magnetic field reacts with said first-mentioned magnetic field, a source of periodically varying electromotive force for energizing said winding to cause the latter to produce a varying magnetic field reacting with said unidirectional field to effect oscillation of said winding and said movable means by the reaction between said two fields, a-source of unidirectional electromotive force, and means energized by the latter and mechanically connected to said movable means for, producing a unidirectional magnetic field to coact with said first-mentioned unidirectional magnetic field to thereby affect the stroke of oscillation of said movable means. I

9. An apparatus as claimed in claim 8 in which the means energized from said source of unidirectional electromotive force comprises a winding adjacent said first-mentioned windingand therebypositioned so that its unidirectional magnetic field coacts with said first-mentioned unidirectional field.

10. An apparatus as claimed in claim 8 in I which the means energized from said source of of electromotive force, said circuit connections including electro-responsive current-blocking means for preventing the energy from one of said sources from reacting upon the other source.

12. An apparatus of the character described in which there is a lens system having a plurality of lenses between which relative axial movement may take place and which are corrected to produce, at the image plane of said system and for a certain range of said relative movement, equalfocus images of a scene or object corresponding to a plurality of different planes of sharpness, means mounting said lenses in axial alinement and including movable means capable upon actuation of effecting relative axial movement between said lenses, means connected to said movable means for efiecting movement thereof in recurring cycles and within said certain range, a

plurality of control means therefor for varying the action and for varying the stroke of said' movable means, electromagnetic means reversible in action for biasing the action of said movement-effecting means toward one end of said certain range of relative movement or the other in accordance with the direction of energization of said electromagnetic means, reversing switch means for reversing the energization of said electromagnetic' means and having two positions,

one for each direction of energization, and means- 13. An apparatus as claimed in claim 12 in which said'control means are electro-responsive devices individually operable, a selector switch substantially synchronized with said reversing switch means for determining which of said dement may take place and which are corrected toproduce, at the image plane of said system and for a certainrange'ofsaid relative movement, equality of size and registry of in-focus and outof-focus images of a scene or object corresponding to a plurality of different planes of sharpness, means mounting'lsaid lenses in axial alinement and including movable means capable upon actuation of effecting relative axial movement .be-

vices is at any time to be effective, said reversing switch means and selector switch being constructed so that said selectorswitch may be acmated to select one of several of said devices for 1 o tween said lenses, actuating means for said movable means having a plurality of control means therefor, movable diaphragm means for controlling the light'passing through said lens system to the image plane, actuating means for effect: ing movement of said diaphragm means and having a plurality of control means therefor, and selector means for determining which of each of said plurality of control means is to be currently efiective to thereby permit setting of ineffective control means to be subsequently made effective upon actuation of said selector means.

15. An apparatus as claimed in claim 14 in which said movable diaphragm means is in the form of an iris diaphragm and the actuating means therefor is in the form of a servo-motor, said second-mentioned plurality of control means being in the form of electrical devices each capable of affecting the energization of said motor.

16. An apparatus as claimed in claim 14 in which said movable diaphragm means is in the form of a plurality of movable plate members whose edges outline the aperture and said actuating means comprises an actuating device for each of said plate members, there being means causing said actuating devices to operate synchronously, said second-mentioned plurality of control means being each capable of controlling the action of allof said actuating devices.

17. An apparatus of the character described in which there is a lens system having a plurality of lenses between which relative axial movement may take place and which are corrected to' produce, at the image plane of said system and for 'acertain range of said relative movement, equality of size and registry of in-iocus and out-offocus images of a scene or object corresponding to aplurality of different planes of sharpness, means mounting said lenses in axial alinement and including movable means capable upon actuation of effecting relative axial movement between said lenses, actuating-means for said movable means for effecting oscillation thereof at any one of several frequencies, a" plurality of control means each capable of affecting the frequency at which said actuating means oscillates said movable. means, and selector means for determining which of said plurality of control means is currently effective, thereby to permit setting of an ineffective control means to be subsequently made efl'ective by said selector means.

18. An apparatus of the character described in which there is a lens system having a plurality of lenses between which relative axial movement may take place and which are corrected to produce, at the image plane of said system and for a certain range of said relative movement, equalactuating means to restrict the oscillation of said movable means toward one or the other and of said certain range of relative movement, said .reversible means having a control devicemovable into either of two positions according to the direction in which said reversible means is to act, and means allocating said plurality of control means in two groups, one group for each direction in which said control member is moved,

whereby for each direction in which said reversible means acts one group of control means is available. j

19. An apparatus of the character described in which there is a lens system having a plurality of lenses between which relative axial movement may take place and which are corrected to produce, at the image plane of said system and for a certain range of said relative movement, equality of size and registry of infocus and out-of-focus images of a scene or object corresponding to a plurality of different planes of sharpness, means mounting said lenses in axial alinement and including movable means capable upon actuation of effecting relative axial movement between said lenses, means energizable by aperiodically varying electromotive force for oscillating said movable means at a'frequency that is a function of the periodicity of said electromotive force, reversible electromagnetic means ,for acting upon said movable means to bias its oscillation toward one or the other end of said range of relative movement according to the direction in which it acts, a reverse control for said reversible electromagnetic .means, and two groups of selectable control means for changing the periodicity of energization of said oscillating means, one group for each direction in which said reverse control'mak'es said reversible electromagnetic means effective.

20. An apparatus as claimed in claim 1 in which there is reversible means for shifting the actual relativemovement toward oneend or the other; of said range, and a control for said reversible means. I

- PHILIP STANLEY SMITH. 

